Q: I recently purchased a new car, and it came with nitrogen-filled tires as part of the dealer’s accessory kit. The next morning after driving the car home I checked the tire pressures. All four tires measured 37 pounds per square inch. The door-jamb tire information placard states the front tires’ pressure should be 32 psi, and the rear 30 psi. I lowered the pressures to the specified amounts.
I understand nitrogen is not subject to temperature changes. A few days later we had a cold snap and I rechecked the pressures and found them to be down about 1-2 psi. Is there any way of checking to make sure there is really nitrogen in my tires?
A: When you bled down the pressures, did you laugh uncontrollably? Oh, wait, that would be nitrous oxide, not pure nitrogen. And by the way, no one said nitrogen was not sensitive to temperature changes, just less so than good ol’ air.
Typically, a colored valve stem cap is used to identify tires filled with nitrogen.
I do not know of any kind of physical or chemical test to prove nitrogen is the gas in your tires, but you could try a relatively simple experiment. If your new car came equipped with a full-size spare tire, fully deflate it to expel any nitrogen, then fill it to the same cold pressure as your car’s tires. Every six months check the pressure in the spare tire. If the pressure is measurably lower than the vehicle’s tires, the car’s tires are filled with nitrogen.
Anyone else know of a method to confirm nitrogen in a tire?
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Q: I own a 2012 Volvo S60 with 36,000 miles and a 2005 Jaguar XK8 with 65,000 miles. Both have ZF automatic transmissions, which are supposed to not need to be flushed or otherwise maintained. The Volvo’s manual says not to change the engine coolant. I don’t drive either one hard and haven’t had problems. What do you think about the no-maintenance instructions?
A: For your Volvo, you are correct that Volvo has no service recommendation for coolant changes.
And under “normal” driving, no recommendation for routine transmission service either. But I did find a note in my ALLDATA automotive database that Volvo does recommend transmission service every 52,000 miles if the vehicle is used for towing or if a message appears on the dash. Turning to your Jaguar, I find no service recommendation for the transmission although, like your Volvo, it’s fitted with both a drain and fill plug for servicing.
Both carmakers suggest brake fluid replacement every two years, and Jaguar would like you to change the coolant every five years.
All I can tell you is that despite my difficulty accepting these no- or long-interval transmission service recommendations, I do recognize significant improvement in lubricants used in modern automatics. Many carmakers and oil companies develop specific lubes for use in their engines and transmissions. Ditto coolants.
My problem is that I cannot fathom how the additive packages blended into these lubricants and coolants will not degrade, oxidize or be consumed over 100,000-plus miles and many years of driving.
Remember my maintenance mantra: “I own the vehicle and am responsible for its maintenance, not the carmaker.”
• • •
Motoring note
In regards to the 2006 Mazda Tribune whose key fob would not unlock its doors nor start the car, here’s a possibility I hadn’t thought of. Thanks to Janice Wilson for this: “I too had issues with my Mazda CX7 remote sometimes not working and then it would — very annoying. Do you know what it was? It happened when the remote and my cellphone were beside each other in my purse! Never happened since I have different spots for each of them now.”
Dang cellphones. Not only a dangerous distraction, but an evil electronic jamming device. Who knew?
Paul Brand, author of “How to Repair Your Car,” is an automotive troubleshooter, driving instructor and former race-car driver. Readers may write to him at: Star Tribune, 425 Portland Ave. S., Minneapolis, Minn., 55488 or via email at [email protected]. Please explain the problem in detail and include a daytime phone number.
Because of the volume of mail, we cannot provide personal replies.
You can’t tell if a tire is filled with nitrogen or air by just simply looking at the tire.
The common way to identify a nitrogen-filled tire is by fixing a compact nitrogen analyzer to the tire’s valve cap. This will display the percentage of nitrogen gas in the tire. The tire is inflated with nitrogen if the analyzer reads 95 percent or more.
However, a reading with 78 percent nitrogen means the tire is air-filled. If the percentage falls between 80 to 95 percent, the tire is filled with a mixture of nitrogen and air.
Meanwhile, it’s quite challenging to use a nitrogen analyzer. But, as a technician who has to fix multiple tire problems day in and day out, there is a simple way I identify nitrogen-filled tires.
Table of Contents
Simple Way To Tell a Tire is Filled With NitrogenInstead of a Nitrogen analyzer, you can use a green N2 (signifying nitrogen) button on the top of the tire’s original valve stem cap.
Many vehicle owners use this method since it is more straightforward.
Filling your tires with nitrogen instead of air has many benefits and tradeoffs. Since nitrogen seeps out of tires more slowly than compressed air would, it will extend the tire life, reduce uneven tread wear, and even increase gas mileage.
However, using nitrogen-filled tires involves responsibilities, including regular checks and frequent inflation.
Now that you know how to identify a tire filled with nitrogen, we will run through the steps involved in checking the tire pressure in nitrogen tires and other relevant answers to nitrogen tire questions.
Can You Plug A Tire Filled With Nitrogen?
In the event of a puncture, the gas in your tire is irrelevant with using a puncture sealant. After all, compressed air contains 80 percent nitrogen.
Plugging a nitrogen-filled tire could muck up the inside of the tire and damage the TPMS sensor stem and the valve seal.
Tire dealers recommend not to plug a tire filled with nitrogen since it can throw your tire’s balance out to the wind.
Can You Put Air In A Tire Filled With Nitrogen?Yes, you can. There is nothing dangerous in putting air in a tire previously filled with nitrogen. Again, compressed air is made up of about 78 percent nitrogen, 20 to 21 percent oxygen, and 1 to 2 percent water vapor and other gases.
The only thing you should be concerned about when topping off a nitrogen-inflated tire with air is the possibility of diluting the purity of the nitrogen. As a result, all the benefits of using an effective nitrogen-filled tire will decrease.
So you can put air in a tire filled with nitrogen as both gases do not react adversely.
Do Tires Fill With Nitrogen Lose Pressure In Cold?
Nitrogen is a gas and can’t twist the law of physics. It will be affected by ambient temperature drops during the fall/winter months.
As tire pressure drops, the nitrogen-filled tire will require pressure add-up (more on this shortly)
Meanwhile, the molecules in nitrogen are bigger than those in normal air. So they barely leak out, so they will maintain air pressure longer.
How Do I Check Nitrogen Tire Pressure?
As mentioned earlier, regular checks and inflation are part of nitrogen-inflated tire users’ responsibility. The steps I use to check the tire pressure of my nitrogen-filled tires are the same as those of tires filled with compressed air.
First, you need to find out the recommended tire pressure for your vehicle, then unscrew/remove the valve cap from one of the tires.
Afterward, take the tire’s valve stem and connect it to the inflow valve of your tire pressure gauge. The current inflation of the tire will be displayed. Note this down, then disconnect the gauge from the tire’s valve stem.
The tire pressure may be low, so you need to add nitrogen.
If otherwise, you are good to go. Then, replace the valve stem cap and repeat the process for the other tires on your vehicle.
Nitrogen Vs. Compressed Air: Which Is Better for Your Car Tires?
There is quite a trendy debate over whether nitrogen or compressed air is better for inflating tires. But, of course, the ultimate decision is influenced by your preference.
If you have a nearby nitrogen source, are willing to observe regular pressure checks, and prioritize optimal tire performance, then nitrogen is worth your shot (and the extra cost.)
If these caveats don’t sit right with you, you are better off inflating with compressed air.
Moreover, unlike air, nitrogen will maintain its inflation longer and improve overall vehicle handling.
Also, since they do not introduce any water into the tire, there is no corrosion. But skeptics would point out that nitrogen refills aren’t as readily available as air, and the cost of getting refills can be as high as $7 per liter for a top-off.
In summary
The use of nitrogen-inflated tires is catching on with many vehicle owners. In the above article, we have looked at the two common (and pretty straightforward) ways to tell if a tire is filled with nitrogen or compressed air.
P.S. A portable nitrogen analyzer can set you back around $200. I use this Portable Nitrogen Dioxide Detector 0-20 PPM Range with LCD Display Backlit, which I purchased for $282 on Amazon.
Remember, using puncture sealant on nitrogen-filled tires can damage your TPMS sensor stem and the valve seal. But there is nothing wrong with putting air in a tire that has previously been inflated with nitrogen.
Let me know in the comments if you have any doubts about using nitrogen to inflate your tires.
What is better - free air or "magic" nitrogen in tires? There are a lot of opinions.
Those who pumped nitrogen into tires instead of air recommend that their acquaintances and friends do the same. Many have heard that Formula 1 cars use nitrogen to inflate tires. Yes that there "Formula 1"! Aircraft tires, heavy trucks and supercars also contain nitrogen. Opinions were divided.
What are the advantages of nitrogen over oxygen in tires, is there any difference at all, or is it a banal pumping out of money? “Sellers of air” name such pluses:
| - stable pressure in tires, as a result of which wear is reduced; - smooth running of the car; - good road grip; - in the event of a tire puncture, the leakage rate is less; - regardless of the temperature in the tire constant pressure; - good fuel economy. |
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At first glance, for little money, how many useful and important properties at once! Modern car owners love all sorts of exotic things, like miracle powders, wiper spoilers that supposedly improve aerodynamics, etc.
They also seized on this "innovation" with nitrogen in tires.
If you recall the physics from the school course, it is clear that "air" consists of 78% nitrogen, 21% oxygen, 1% carbon dioxide and other gases. And the mixture advertised by tire fitters consists of 95% nitrogen and 5% oxygen.
« Stable tire pressure. Since the coefficient of thermal expansion of nitrogen is lower than that of air, the effect of ambient temperature on the tire has practically no effect on the pressure inside it. Nitrogen does not expand at all, unlike air. Therefore, it is nitrogen that is ideal for pumping into tires. »
| However, anyone with even a little knowledge of physics understands that the statement that the pressure of a gas in an enclosed space is independent of temperature conflicts with the laws of Gay-Lussac (for any gases, the volume expansion coefficient is the same) and Charles (the pressure ratio to temperature is a constant value). |
Accordingly, the change in tire pressure will be about 0.00025 atm. Is this a significant change? Certainly not. For those who do not believe in science, we can advise you to conduct a small experiment on your own: pump one tire with nitrogen, and the other with air, and alternately immerse it in boiling water, then in ice water. It is unlikely that the pressure will be stable.
« A tire filled with nitrogen never deflates. Nitrogen molecules are very large, much larger than oxygen, and they move extremely slowly through the micropores in rubber. »
| Again we turn to physics. |
Perhaps the whole secret is that “large” nitrogen molecules seem to clog the micropores of the tire and do not allow molecules of other gases to pass out? Although the mixture advertised by the sellers contains 16-17% more nitrogen than ordinary air
« The possibility of tire explosion is minimal. Because nitrogen is an inert gas and does not support combustion. At high speeds, the tire does not heat up because there is no combustible oxygen in it. »
| So, let's try to understand all this.
|
A normal tire for a passenger car can withstand pressure up to 9atm. In order for a tire to burst, it must be heated to a temperature of at least 1000 ° C. At this temperature, even a steel disk will melt.
« Fuel economy. A wheel filled with nitrogen is lighter in weight than a wheel filled with air. Accordingly, the load on the suspension is less and fuel consumption is reduced. »
| At first glance, everything is logical. But let's calculate what is the difference in the mass of wheels pumped up with nitrogen and air. |
This means that the nitrogen content in this tire will be 0.0750 kg, and air - 0.0774 kg. That's the whole difference! You just need a jewelry scale to catch such a difference in weight. Naturally, there can be no talk of any difference in weight and fuel economy.
« Delayed tire aging due to the absence of dust, moisture and oil in nitrogen. This is confirmed by tests conducted by Continental, Bridgestone, Michelin. »
| If you think about it, the impact of the environment (various reagents on the road surface, ultraviolet radiation, bitumen, etc.
|
Is it really possible to save the carcass of tires from oxidation by ordering nitrogen into the tire, as the “air sellers” promise? This is hard to believe, since it is well hidden in the thickness of the rubber and cannot come into contact with air, moreover, the wires of the frame are covered with brass and are not easily oxidized.
« Improving road grip. Nitrogen is more stable than air (which is able to succumb to the environment) . »
| This myth is generally difficult to somehow comment on. There is nothing to discuss, no matter how you look at it.
|
On the other hand, cunning sellers sometimes deliberately underfill the tires with nitrogen and warn the client not to inflate the tires with air in any case, and also not to check the pressure.
So nitrogen in tires, instead of ordinary air, is not an innovation at all, but rather a tribute to fashion, which is usually not consulted with science. On the other hand, the small money that is given to the “air sellers” for nitrogen may well be compensated by the impression made on friends when saying the phrase: “And in my car there are nitrogen tires, like Schumacher’s!”.
Green caps on the wheel valves usually indicate that the tires are filled with nitrogen, not ordinary air.
Car dealerships, tire dealers, repair shops, and even some gas station chains have long touted nitrogen as an alternative to replacing air in tires, talking about its benefits. As a result, filling tires with nitrogen has become popular among some car owners. Today we will try to figure out who the nitrogen supporters are right or those motorists who prefer to inflate the wheels with air, what is this marketing or a real step forward.
1. Advantages of tires with nitrogen filling
2. Criticism
3. What is science and research
4. Where did the fashion for nitrogen
5. does it make sense to fill tires with nitrogen
6. Conclusion
7. Frequently asked questions and answers to them
in them falls more slowly than if they were filled with air. This is true, because nitrogen molecules are larger than oxygen molecules, of which air is partly composed.
This allows you to think that, the pressure in tires filled with nitrogen, you can check less often, or even completely forget about this procedure. The advantages of ideal constant tire pressure are: reduced fuel consumption, extended tire life, good vehicle handling. Also, supporters of the use of nitrogen say that due to the moisture contained in the air, dry rotting of tires, corrosion of disks, and failure of TPMS sensors occur. Nitrogen filling, on the contrary, guarantees the absence of moisture and prevents all these undesirable processes. In addition, it provides a more stable temperature inside the tire.
The first thing to start with is that a tire filled with nitrogen contains not 100% of this gas, but from 93 - 95%, while ordinary air is 78% nitrogen, so the difference is not so small.
The next thing is that nitrogen still leaves the tires over time, although not at the same rate as air. Therefore, when using nitrogen, you will still need to check your tire pressure from time to time to make sure it is still at the recommended level.
In addition, whether a tire is filled with normal air or nitrogen, it will lose pressure if, for example, its valve is defective, or the tire is not installed and sealed properly, or the tire has any damage. Changes in air temperature also cause pressure fluctuations in tires filled with nitrogen.
It is also important that filling tires with nitrogen costs money, and places where you can do it along the way are rare, so you need to go specifically to fill the tires, instead of doing it with a regular pump in your garage.
For these reasons, many tend to believe that the benefits of nitrogen are exaggerated.
All gases expand when heated and contract when cooled, and so does tire pressure. Tire pressure can rise and fall as the ambient temperature changes. In fact, ambient air contains about 78% nitrogen, 21% oxygen and 1% other gases, as stated above, nitrogen for tires contains 93 - 95% nitrogen.
The difference is not that big, so why is nitrogen used?
1. First of all, because nitrogen is an inert (non-combustible) gas, in fact, it is nothing but air with oxygen and moisture removed. In some areas, the inertness of nitrogen comes in very handy.
2. Tires naturally lose air over time, especially when they are subject to temperature fluctuations. This is because tire walls are porous at the molecular level. When a tire heats up, the air inside it expands. The extra pressure pushes a small amount of air through the pores, so sometimes you have to pump air even if the tires are intact. In theory, nitrogen tires don't lose pressure as quickly as air tires because nitrogen molecules are larger than air molecules. This means that a nitrogen-filled tire will require less frequent inflation.
At the same time, the American magazine Consumer Reports, which publishes reviews and comparative tests of consumer goods and services, has conducted research on this subject.
Surprisingly, the researchers found only a negligible difference in deflation between tires filled with nitrogen and tires filled with regular air. On average, tires filled with air showed a loss of 0.24 atmospheres, and tires with nitrogen lost an average of 0.15 atmospheres after 12 months - this is not a difference that is enough to clearly affect fuel consumption or tire wear. In addition, the US Tire Manufacturers Association also issued a statement regarding the practice of using nitrogen to fill passenger tires. According to them, nitrogen "can contribute to a slight reduction in tire pressure loss."
Nitrogen came to passenger car tires from highly specialized areas, where its inertness (non-flammability) is primarily important. For example, it is used for refueling aircraft tires, mining equipment. In addition, its popularization played into the hands of the use of racing tires in tires. Nitrogen is used in professional racing, where extreme speeds are involved.
Nitrogen reduces tire pressure fluctuations. In competition conditions, even small drops can affect handling, and, consequently, the result.
In general, nitrogen filling is not required for ordinary consumer tires, however, this does not harm the tires and may slightly help reduce pressure loss. It makes perfect sense to fill tires with nitrogen when buying a new car with new tires being filled for the first time, also when you have extra income and love your car. There are stronger arguments in favor of using nitrogen, but they do not apply to passenger cars. For example, this makes sense in the harsh conditions of tires in the commercial trucking industry.
In a debate between those who choose nitrogen/air, there doesn't have to be one answer. Regardless of what you fill your tires with, the most important aspect of tire maintenance is maintaining the correct pressure. Properly inflated tires wear more evenly, save fuel, improve handling and last much longer.
1) Can you mix air and nitrogen? - So, you filled up the tires with nitrogen, but during the trip you noticed that the tire is flat. Nitrogen is not available at nearby gas stations. Is it possible to inflate the wheel with air? Certainly! Mixing nitrogen and air does not lead to adverse chemical reactions, but only reduces the density of nitrogen and its effectiveness.
2) How safe is nitrogen? - As safe as normal air. Nitrogen is non-flammable and chemically harmless.
3) Can I reduce fuel consumption by using nitrogen? - You will always get the best fuel economy on properly inflated tires, whether filled with nitrogen or air.
4) Does nitrogen prevent dry rotting of tires? Disc corrosion? - Compared to air, nitrogen is a "dry" gas, so it doesn't release as much moisture inside the tires. However, rubber rotting due to moisture inside the tires is extremely rare. It is much more likely that the tread will be worn out before the tire begins to decompose from dry rot, unless the car is laid up.
We can conclude: all statements that nitrogen will behave differently than oxygen, with an increase or decrease in temperature, are real inventions that are designed for an uneducated person. Of course, there is still a small difference in the volume expansion coefficient, but it is only 0.0001. 
The size of a nitrogen molecule is 0.364 nm, and an oxygen molecule is 0.346 nm. This difference is not perceptible by any manometer. An old tire with cracks will deflate in any case, no matter what it is inflated with. And a high-quality one is able to maintain pressure for years, releasing it only through a valve or a joint between the rim and the tire. 
If you look at the periodic table, you can immediately see that inert gases are in group 8, and nitrogen belongs to group 5. This is one. The most important thing is that the tire bursts, and does not explode, the sound that is heard at the same time is a pressure surge from the shock wave. 
1 cubic meter of air contains 78% nitrogen - this is 1.29kg, and pure nitrogen - 1.25 kg. For example, let's take a common wheel with a 165 / 70R13 tire and calculate the mass of gas in it. The volume of such a tire is approximately 20 liters, the excess pressure will be 2 kgf / cm2, i.e. it is easy to calculate that there are approximately 60 liters of gas in such a tire. 
) on the tire is much larger than the impact of the internal filler. In addition, for particularly scrupulous car owners, it is not a problem to pump clean air into the tire, for this it is enough to purchase a compressor with a dryer and a filter. 
Anything (the condition of the road itself, the design of the tire, the quality of the rubber from which the tire is made, the distribution of stress in the contact patch) affects the grip of tires with the road surface, but not the gas that is pumped into this tire. 
